code: def test_value_to_json(self):
      print()
      json = serialize._value_to_json(Union[str, int], 6)
      self.assertEqual(SAMPLE_INT_JSON, json)
  
file_path: pytext/pytext/config/test/serialize_test.py
imports: import unittest
  from typing import Any, Dict, List, Union
  from pytext.config import ConfigBase, pytext_config_from_json, serialize
label_desc: Use image node_id 2 for calling the SerializeTest obj's underlying member method code with example usage: obj.test_value_to_json() without return types